CONSOLIDATED BALANCE SHEETS - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 86,832,000	$ 84,265,000
Short-term investments	164,637,000	231,233,000
Escrow deposits, current		220,000
Prepaid expenses and other current assets	4,465,000	4,003,000
Total current assets	255,934,000	319,721,000
Property and equipment, net	85,842,000	82,785,000
Operating lease right-of-use assets	28,207,000	28,945,000
Restricted cash	1,979,000	1,979,000
Long-term investments	83,316,000	51,854,000
Security deposits	950,000	1,260,000
Total assets	456,228,000	486,544,000
Current liabilities
Accounts payable	3,475,000	5,454,000
Accrued expenses and other liabilities	6,531,000	9,841,000
Deposit liability	881,000	866,000
Long-term debt, current	10,297,000	6,502,000
Deferred revenue, current	6,500,000	7,154,000
Total current liabilities	27,684,000	29,817,000
Operating lease liability, long term	41,168,000	38,698,000
Deposit liability, non-current	433,000	718,000
Deferred revenue, non-current	109,768,000	110,834,000
Long-term debt, net		3,739,000
Total liabilities	179,053,000	183,806,000
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $ 0.0001 par value, 10,000,000 shares authorized and 0 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively
Common stock, $0.0001 par value, 125,236,190 shares authorized; 59,106,784 and 58,473,660 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	6,000	6,000
Additional paid-in capital	828,806,000	824,292,000
Accumulated deficit	(550,362,000)	(519,098,000)
Accumulated other comprehensive loss	(1,275,000)	(2,462,000)
Total stockholders' equity	277,175,000	302,738,000
Total liabilities and stockholders' equity	$ 456,228,000	$ 486,544,000